Effect of a 12-Week Football Programme on Body Composition, Physical Condition, and Analysis of Physical Demands in Young Male Children

The aim of this study was to describe and analyse the effects of a 12-week football programme on body composition (fat mass, muscle mass, and bone mass) in children compared to a sedentary lifestyle, as well as the physical demands and loads required in training and matches in young football players (U10-U12). Forty children were included, divided into two groups: a football group (FG; n = 20) and a control group (CG; n = 20). Body composition was analysed using DXA and physical demands were analysed using GPS, with a total of 504 observations. Total bone mineral content (BMC) was significantly increased in FG-U12 (p = 0.025) after training. Total bone mineral density (BMD) was increased after the 12 weeks in FG-U10 (p = 0.001) and FG-U12 (p = 0.002). Leg BMC in FG-U10 (p < 0.05; 2.2 to 7.1 g) and FG-U12 (p < 0.05; 2.0 to 17.0 g) was increased after 12 weeks. VO2 max after training was significantly improved in FG-U10 (p < 0.05; ES: 1.7 to 5.2 mL/kg/min) and FG-U12 (p < 0.05; 0.3 to 3.8 mL/kg/min). Among U10s, midfielders covered greater distances and had higher intensity accelerations (p < 0.05; ES: 1.05 to 2.00) than forwards and defenders. Among U12s, midfielders in matches covered greater distances and at higher intensity than in training (p < 0.05; ES: 1.05 to 2.39). Football practice produces benefits in total and lower limb BMC, BMD, and VO2 max. The training and position of midfielders require higher physical demands.